my engine went boom pics

If you did check PTV properly then that is for sure a valve float problem. The good pushrods wouldn't have helped you. 7k is a lot of RPM for a hyd roller sbf with those heavy lifters, you need the right hardware to do it.
 
Definatly a valve float PTV issue. Pull the other head off and I bet you will see marks in the other pistons from the valves touching.

What heads and what cam?
 
the heads were c9oe castings but there were milled quite a bit. the cam was a custom comp grind. 248*/254* at .050" lift was right about .550". the cam made peak power at 6800 and comp matched the springs to the cam. it was a double spring with a damper. i guess we all learn from our mistakes...time to build a new one.
orangejuiced86 said:
Definatly a valve float PTV issue. Pull the other head off and I bet you will see marks in the other pistons from the valves touching.

What heads and what cam?
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foxbodydave said:
the heads were c9oe castings but there were milled quite a bit. the cam was a custom comp grind. 248*/254* at .050" lift was right about .550". the cam made peak power at 6800 and comp matched the springs to the cam. it was a double spring with a damper. i think one thing i didnt take into effect is the fact that the heads were milled so much. i guess we all learn from our mistakes...time to build a new one.
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You said you checked the PTV clearance?
 
Not enough piston to valve + valve train float caused this, you can see the contact on the pistons and the valves.
 
well there is some good light at the end of the tunnel!! i just got a 306 complete motor with gt40p heads...all new bearings and rings and a flat tappet cam for 500 bucks!! everything is proven to work together so i should be good!!
 
Worn out valve guides can cause valves to break also. The valve will hit one spot on the seat before closing all the way, putting stress on the valve head. The guides gotta be pretty blown out to make that happen tho.
 
foxbodydave said:
yes, i was getting ready for my 1-2 shift
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I'm sorry about your carnage really blows!
but i was there and watched you do that... certainly sounded like you missed second and then it over rev'ed...
:bondage:

not starting shit...just sayin...

DRAG-ULA said:
Worn out valve guides can cause valves to break also. The guides gotta be pretty blown out to make that happen tho.
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it seamed like it was smoking a bit to before hand:headscrat
 
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i hit second gear just fine. and thats when the motor just shut down...
sandman56 said:
I'm sorry about your carnage really blows!
but i was there and watched you do that... certainly sounded like you missed second and then it over rev'ed...
:bondage:

not starting shit...just sayin...



it seamed like it was smoking a bit to before hand:headscrat
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looks like Valve Float.
If you bent a Pushrod either it wouldnt open or wouldnt open enough. think about it, when a pushrod bends, the overall length is shorter so the valve couldnt have opened all the way. Looking at the Carnage I say Valve Float.
 
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